Recently, vehicle lamps equipped with a laser scanning unit are known. In a laser scanning unit of a mechanical-optical system described in Japan Patent Publication No. 2013-125693, a laser beam is scanned using a laser scanning unit such as an MEMS (Micro Electro Mechanical Systems) mirror, a galvano-mirror or the like, so that a mark denoting a road sign is shone on to a road surface or the like.